Our twin boys just turned 15 months old, and it’s amazing how different they are already. Granted, they are fraternal/dizygotic twins, but they share an age, a bedroom, and their environment. And they look alike, too. Not enough to confuse us on most days, but both blond-haired and blue-eyed. And that’s where the similarities generally end.

1. Sleeping

The first difference is evident early in the morning, as the older boy is an early riser. He’s usually ready to get up at around 7 or 7:30. And while I know that some parents would kill for that, it doesn’t quite fit our schedule. Besides, his brother and their older sister happily snooze on until 8:30 or 9:00. So it falls to one of us to get up with him for special 1-on-1 early morning play time (I admit that sometimes this involves me snoozing on the couch downstairs). A few times we’ve had to undertake rounds of baby sleep training because he wakes up in the middle of the night to eat.

2. Eating

I suppose it’s not terribly surprising to learn that twins have different food preferences. They’re both eating mostly finger foods now. Since the age of six months, the older boy’s been rather picky. He’ll try eating for 15 minutes and after that he’s ready to get down. In the other high chair, his younger brother eats anything you put in front of him (despite being a couple of pounds lighter). I mean, anything. More recently, both twins have developed the bad habit of dropping anything they don’t want on the floor.

There are certain foods (like peas) that we can only get one of the twins to eat. Whenever we find something that both of them really like (spaghetti is one example), we make note of it and get that food into the rotation!

3. Crawling and Walking

The older twin crawled first, and by this I mean the “classic” hands and knees crawl. And he was fast. His brother was immobile for a couple of weeks, then developed the “wounded man crawl”. Far more arduous, and much slower. It took him another couple of months to switch to traditional crawling, and by then, the older twin was a confident walker.

It’s conventional wisdom that babies with older siblings learn to walk faster, but I don’t know if this is true. Certainly the motivation was there: when your older sister can simply run off with a disputed favorite toy, it inspires you to walk pretty quickly! Quite honestly, I think that the age at which babies learn to walk is affected by numerous factors:

Development stage. Our twins were preemies, so their adjusted age is 6 weeks younger. Their growth and skill development reflects this; when evaluated against children with the same actual age, our boys are in the 10th or 20th percentile for most measurements (height, weight, head circumference). The pediatrician assures us that they’ll catch up within a year or so.

Physical strength. There’s both a “nature” (genetics) and a “nurture” (training) component to this. Simply put, learning to crawl and walk takes a certain amount of strength, balance, and coordination.

Environment and personality. I’ve heard it said that babies in day care, who spend their days around numerous older children, tend to learn new skills more quickly. In my opinion, it’s also a matter of the baby’s habits. Part of why we think our younger twin is behind is simply that he’s more content in nature. He’ll happily stay in one place and play with whatever toy is in reach, while his brother constantly seeks out new stimulation.

4. Interests

Given the freedom to explore a room, our twins behave very differently. The older one is the troublemaker. Anything you left out, he makes a beeline for. Drinks. Pens and papers.Laptops. Food or kitchenware. It’s actually a great way to baby-test a room: put him down, and see where he goes. Because if there’s something he shouldn’t have, he’ll find it. Lately he’s taught us that things on the couch or kitchen table are now within his reach. Whenever he goes quiet, you know he’s gotten into something. He’s our motivation for finding new ways to contain and entertain our twins.

The younger twin doesn’t seem to have the same penchant for mischief. He’s generally quiet happy with the first toy he finds. The only thing that really draws his interest is an open laptop, which he likes to treat like a drum set. I can’t tell if he loves my Macbook or hates it. Sometimes he’ll just shove it off of a low table and onto the carpet.

5. Temperament and Personality

This is perhaps one of the better known differences between twins (even identical twins) and I find it very fascinating: every one has a different personality. This manifests in so many ways: how they play, how they spend their free time, how they interact with us and with others. Our older boy is high maintenance. He craves a lot of attention, he wants to be held all the time. He’s also the show-stealer and notorious flirt – he smiles, makes cute faces, and really turns on the charm for total strangers. He’s the one who brings them over from across the street or the other side of the restaurant.

At this point, most people notice that we have twins. The younger boy is the total opposite. He’s quiet. He keeps to himself. I get the feeling he could take us or leave us. He’s so laid back; a lot of times we just forget that he’s there. Around bedtime, he cleverly uses this to his advatage: many times he’ll crawl out of sight, play quietly with some toys, and buy himself an extra half hour. When strangers come up, he plays it shy, with a little smile and then turning away. And everyone just eats it up.

6. Future

I can’t help but think about how these differences, magnified over time, will undoubtedly lead to very different lives for our twins. Granted, they’ll share a close connection as twins usually do. But their interests, personalities, and chance events will probably set different courses in life for them. I know they’ll be put into different classes at school; that might lead to two independent sets of friends, better or worse grades, different colleges, different careers.

But I suppose after all those days of getting dressed alike, they’ll probably look forward to it.